Railway truck bolster suspension



`June 6, 1950 J. c. TRAvlLLA, JR

ENSION RAILWAY TRUCK BOLSTER SUSP 2 Sheets-Sheet 1 Filed April 24', 194s lNvENToR'. JAMES C. TRAWLLA; JR.

ATTORNEY.

J. C. TRAVlLl-A, JR RAILWAY TRUCK BOLSTER SUSPENSION June 6, 1950 2 Sheets-Sheet 2 Filed April 24, 1948 mvENToR: JAMES C. TRM/LLA, JR.

BY @M7 M ATTORNEY` Patented June 6, 1950 UNITED STATES .PATENT `,()FFICE 2,510,353 RAILWAY TRUCK BOLSTER SUSPENSION James C.

signor The invention relates to railway rolling stock and more particularly to railway trucks of the type described in Patent No. 2,163,253, issued June 20, 1939, to EmilC. Anderson, and in which the load-supporting bolster is carried by springs mounted on a multiple part spring plank suspended by swing hangers from the truck frame.

The several parts of the multiple part spring plank as used heretofore are separated by rollers which roll on concaved seats on each of the parts and provide for relative lateral movement of the parts due to lateral shocks induced by rail joints and other track irregularities, variations in wear of the wheel tread and draft and buffmg forces. Relative movement of the spring plank parts is not adequately damped or cushioned to provide a smooth riding truck at the high speeds at which railway vehicles are operated today. The parts, after movement relative to one another from their normally centered position by a lateral force, upon their release from the force, move to and fro relative to one another and past their normally centered position.

One object of the invention is to adequately cushion or damp the movement of the spring plank parts to reduce the tendency of the spring plank parts to move past their normally centered position after their release from a lateral force.

Another object is to reduce wear of the spring plank parts to a minimum.

Another object is to simplify construction of the truck yet provide, in a two-part spring plank truck, substantially the same flexibility and riding qualities as in a conventional triple bolster truck.

Other objects will be apparent to those skilled in the art from the following description and accompanying drawings, in which:

Figure l is a top view of a of the center portion of a railway structed according to the invention, being sectioned horizontally on the line Figure 2.

Figure 2 is in part a side view and in part a longitudinal vertical section taken approximately on the line 2--2 of Figure l.

Figure 3 is a transverse vertical section taken approximately on the line 3-3 of Figure 2 and drawn to enlarged scale and showing the spring plank parts in their normal positions.

Figure 4 is a View similar to Figure 3 drawn to enlarged scale and showing the spring plank parts displaced laterally relative to one another.

Figure 5 is a bottom view of the upper spring plank part and the adjacent truck parts, with a portion I-I of Travilla, Jr., to General Steel Castings Granite City, Ill., a corporation of Delaware Application April 24, 1948, Serial No. 22,990 6 Claims. (Cl. 105-190) University City, Mo., as-

Corporation,

the supporting pads applied to the spring plank. The truck includes the usual wheels I, axles 2 and journal boxes 3. Equalizers 4 are mounted on boxes 3 and mount truck springs 5 which 5 carry a truck frame' 6. The truck is n.of the lateral motion bolster type and has pairs of swing hangers 1 at opposite sides of the truck pivotally suspended from frame 6 by pins 8. Each pair of hangers 1 carries a cross bar 9. i0 A twopart spring plank I0 has a lower part II and an upper part I2 extending transversely from side to side of the truck. Lower part II is supported at its ends by cross bars 9 and upper part I2 seats a pair of coil springs I3 at each of its ends. Springs I3 carry a bolster I4 having a center plate I5 for mounting a car body (not shown).

A vertically disposed shock absorber 22 at each side of the truck is connected at one end to a bracket 23 on the truck frame and at the other end to a bracket 2li on an extension 21 on bolster I4 and controls vertical movement of the bolster relative to truck frame 6. A horizontally disposed tie bar 25 at each side of the truck is connected at one end to a bracket 26 on the truck frame and at the other end to extension 21 on the bolster and controls movement of the bolster longitudinally of the truck.

A yieldable pad i6 is seated on lower spring plank part II directly below each spring I3 and pads i6 mount upper spring plank part I2. Each pad I6 comprises alternate layers of steel 20 and rubber 2l bonded together.

Opposing faces of spring plank parts II and I2 have seats for the pads to hold them in definite spaced relation. The seats on lower spring plank part II include upstanding ribs I1 of substantially uniform height surrounding the pads. The seats on upper spring plank part I2 include depending ribs I8 extending transversely of the bolster and ribs IBc and Id positioned at the inner and outer sides of the pads. Each rib I8 projects downwardly as indicated at |80. and curves away from the adjacent pads as indicated at Ib. Members Ic near the sides of the spring plank extend downwardly` farther than members Id which are near the center line of the spring plank.

The pads distort in shear when forces are exerted on upper and lower spring plank parts II, I2 in opposite directions, laterally of the truck, thus providing for limited relative movement of parts II, I2 transversely of the truck.

As the pad distorts in shear its successive plates u 20h, 20c, 20d, and 20e move successively increaswould increase uniformly with each unit of relative lateral movement of parts II, l2 until this engagement occurred, but since face IBb is curved, the edges of successive plates engage the face at intervals. As successive plates contact the surface, the effective height of the pad gradually decreases and the resistance of the pad to distortion in shear gradually increases. Hence, the resistance of the pad to relative lateral movement of the spring plank parts II, I2 increases at a rate greater than the rate of increase of relative lateral movement of parts II, I2.

In Figure 4 lower spring plank part I I has been moved to the left of its normal position relative to upper spring plank part I2 and Without any swinging movement of hangers 1. Plates 20a, 20h, and 20c of, pad I6 engage the inner curved portion of rib I8. Plates 20d, 20e, 20j, are spaced from rib I8 and the effective height of 20g. When plates 20d and 20e engage rib I8, the effective height of the pad will decrease to that portion between plates 20e and 20g. Plates 20] and 20g lie below the lower edge of rib I8 and layers 2| bonded to these plates.

The resistance of pads I6 in shear for a certain amount of distortion, such as illustrated, is less than the force required to overcome the static friction between swing hangers 1 and their pins 8 and between cross bars 9 and the spring plank movement of truck frame 6 relative to bolster I4.

Internal friction in pads I6 distorting in shear dissipates the shock forces and cushions or clamps movement of one spring plank part relative to the What is claimed is: 1. In a railway vehicle truck, a frame, hangers pivotally suspended from frame to swing transversely of the truck, a spring plank, a bolster and bolster supporting springs, said spring plank comprising a. lower partv extending from side to side of the truck and carried by said hangers. an

the two spring plank parts.

9. In a railway Vehicle truck, a truck frame,

the projecting rib is rate of increase of lateral deflection.

5. Structure as described in claim 3 in which end of said lower part, up-

of said lower part REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date Bettendorf Jan. 3, 1905 OBrien June 10, 1930 Glas'codine Aug. 29, 1933 Hallquist Oct. 26, 1937 Anderson June 20, 1939 Latshaw Dec. 2, 1941 Nystrom et al. Apr. 27, 1943 Travilla Apr. 22, 1947 

